The present invention pertains generally to lighting, and more specifically to a method and apparatus for collection from, distribution and control of a plurality of lighting sources in a lighting system connected with a network of optical fibers and components, and electric parts.
Electric lighting, a means to supplement natural solar light, offers a number of advantages, yet suffers from several shortcomings. Notwithstanding various improvements to overcome electric lighting""s shortcomings, such as new lighting elements to approximate natural solar light quality and/or to achieve better efficiency, the most prevalent complaints of electric lighting include operating and maintenance cost, light quality, and the heat generated in the conversion process from electrons to photons.
Natural solar light, i.e., sunlight, is a very desirable light source for interior use. However, the only widespread application is the limited use of sunlight with direct exposure, e.g., skylight. While there have been attempts to utilize natural sunlight in various setting, there is no system for wide applicability due to their narrow focus in design.
The present invention overcomes the aforementioned limitations with the following objects:
Flexible, efficient, and novel use of natural solar light source;
Compatible with and complementary to other light sources;
New fixture and architectural arrangements;
Energy savings; and
Ease of maintenance due to centralized lighting sources.
Further objects and advantages of the present invention will become apparent from a consideration of the drawings and ensuing description thereof.
Fiber Optics by Edward A. Lacy, Prentice-Hall, 1982, is a concise and yet practical reference book on fiber optics. Architectural Physicsxe2x80x94Lighting by R. G. Hopkinson, Her Majesty""s Stationery Office, London, 1963 has a comprehensive coverage of lighting in architectural design. Lighting Handbook published by Westinghouse Electric Corp. in 1969, and revised in 1978, contains many reference for illumination engineering.
Optical fiber is gaining popularity for decorative lighting applications. There are many creative lighting fixture designs using various electric light sources. There is also optical fiber designed to provide illumination along its length. The distribution system of these early product offerings is very straightforward with multiple strand of optical fibers running from source to fixture. The intended use of fixtures with optical fiber is for isolated installation.
U.S. Pat. No. 4,720,170 discloses a system for use of solar energy in a commercial building. The main focus is to convert solar energy for other use (heating), in addition to a centralized light source incorporating artificial with the natural light source for channelling through a plurality of light xe2x80x9cpipesxe2x80x9d to the workspaces. Limited control is used with motorized mirrors and shutters.
U.S. Pat. No. 4,246,477 deals with light distribution system using light transmission channel with passive optical components to direct, and to dispense the light. The light transmission channel is constructed using inflexible building materials. Limited control is provided with a light sensing device to control artificial light source, i.e., fluorescent tubes, which are integrated with the natural light output at the fixture in each room.
U.S. Pat. No. 4,761,716 discloses a building design with uses of natural light. U.S. Pat. Nos. 4,785,811 and 4,815,815 continue the use of natural light for medical, and submarine agricultural purposes respectively. The distribution of light once collected is simplistic without integration with multiple sources and without any control features.
U.S. Pat. Nos. 5,285,356, 5,217,285 provide examples of attempts to simulate natural solar light through electrical appliance designs. U.S. Pat. No. 4,820,020 discloses a daylight system with an array of reflectors for increased interior light with limited direct exposure. U.S. Pat. No. 4,557,565 discloses a method using a deflecting panel to direct sunlight into the. interior of a building. U.S. Pat. No. 4,791,533 discloses a system directing sunlight into interior with tilt and direction control. U.S. Pat. Nos. 5,175,967, 5,467,564, 5,655,339, 5,648,873 provide methods to direct natural solar light to area inside a building with direct exposure. U.S. Pat. Nos. 4,943,141, 4,511,755, 5,648,873, 5,467,564 deals with light collecting devices. U.S. Pat. No. 4,669,817 deals with system for time-sharing of light distribution.
U.S. Pat. No. 4,389,085 by Mori discloses a method and apparatus for collecting and distributing sunlight. Mori""s control is limited to moving the sunlight collector to track the position of the sun. Mori""s disclosure deals with singular light collection system, made up possibly of a complex set of light collecting components, at one end of the transmission system. Furthermore, Mori""s embodiments do not integrate electrical light sources with natural sunlight.
U.S. Pat. No. 4,576,436 by Daniel discloses a light system utilizing sunlight with other electrical light sources using a light-conducting rod with a series of beam splitting mirrors. Daniel""s invention is to provide a uniform light distribution a long a fixed length light-conducting rod. However, the integration of various light sources is limited to the location of lighting fixtures, and the use of optical fiber cables is limited of the construct to a light splitting device.
The present invention discloses a method and apparatus for lighting.
A plurality of natural sunlight collecting devices, called collectors, are strategically located in sunny spots on the side or on the roof a building. The collectors can vary in size for ease and cost of manufacturing to achieve the desired light intensity. An array of collectors with or without an accompanying optical network can be used to feed into optical fiber cable (single or multiple stands of optical fiber).
Optical fiber cables with optical components are used for distribution of collected sunlight. Some sections of these optical cables can be placed alongside electrical wiring for ease of installation and access. A bundle of multiple strands of fiber can be used to obtain desired light intensity for cost and ease of handling. The only unique requirement of an optical fiber during the design and installation is the critical turn radius for not breaking its brittle glass or plastic core.
With current optical fiber""s clarity, the loss of collected sunlight through this conduit is negligible comparing with any loss at the connection. Optical fiber cable is used in the long haul for its flexibility in routing through building walls and ducts. Other optical devices, such as reflective, refractive, coupler (directional or star), and splitter can be placed along the path to direct or to siphon off light as desired. A light meter or other similar device can be used to measure the light intensity during installation at each junction point.
Other lighting sources (halogen, neon, etc.) can be introduced at any of the connection points to complement the natural light source for use during night time or for different lighting effects. These light sources do not necessarily have a directional and coherent light output, i.e., laser-like. The only requirement is to focus the light source""s output at an acceptable angle into the optical fiber, which is an efficient conduit with repeated internal reflection. The design and installation requirements deal with providing sufficient light intensity at the output locations with cost and ease of installation and maintenance as parameters.
An adjuster with electrical or mechanical control can be introduced throughout the system for different effects, e.g., light intensity, color filtration, polarization, blocking, etc. A microprocessor is used to control the lighting system at the collector (tilt and direction control), at the electric light source (dim, pattern, etc.), at the distribution points (proportion of light to be siphoned off), and at each lighting fixture, for constant/varying intensity according to time-of-day, time-of-year, weather condition, lighting effects and patterns according to personal preference and presence, etc.
Various lighting fixtures can be used to provide illumination as called for by the architectural design. The availability of natural light sources coupled with other lighting sources to be effected with an adjuster creates a wide range of possible designs. Another major benefit of the present system is the absence of heat at the lighting fixture.
Therefore, the benefits of the present invention are:
flexibility;
cost;
control; and
new architectural possibility.